The effects of fire on pollination haven’t been explored in sexually deceptive systems. Sexually deceptive plants achieve pollination by mimicking the sex pheromone of female insects in order to attract male insects. These systems are highly specialised, with the orchid often being pollinated by a single insect species.
In our new paper, we observed the frequency of pollinator visits to flowers of a sexually deceptive orchid, Caladenia tentaculata, and related it to the post-fire age class of heathy woodland in south-western Victoria.
We also related the number of the pollinator’s putative larval hosts (scarab beetles) captured at these sites to age class. At the local scale, visitation was highest in recently burnt sites. At the landscape scale, positive associations were observed between (1) putative pollinator hosts and vegetation burnt 36–50 years ago, and (2) pollinator visitation and vegetation burnt more than 50 years ago. Local- and landscape-scale effects on visitation were synergistic, such that visitation was greatest when fire age was variable within the pollinator foraging range.
Brown, J., York, A. & Christie, F. (2016). Fire effects on pollination in a sexually-deceptive orchid. International Journal of Wildland Fire. 25: 888-895.
The results of our new paper, available as an Ecological Applications Preprint, suggest that use of patchy fire to break up large expanses of mature vegetation may enhance ecosystem function.
We studied the responses of bird functional diversity to TSF and two direct measures of environmental variation. Six bird functional traits (body mass, clutch size, food type, foraging behaviour, foraging location and nest form) were used to calculate functional diversity.
Functional richness was negatively related to TSF, suggesting that recent prescribed fire creates patchy vegetation and provides greater opportunities for species to partition resources. Buff-rumped Thornbill and Superb Fairy-wren were among the seven species more common in young vegetation than old, and all seven species build dome-shaped nests. This nest type offers better camouflage and shelter against predation than more open nests, but we lack a definitive explanation as to why dome-shaped nest-builders prefer younger vegetation.
We suggest that controlled use of patchy prescribed fire to break up large expanses of mature vegetation is likely to help sustain functional diversity.
Fire Ecology and Biodiversity at UniMelb
Bushfire Behaviour and Management at UniMelb
Quantitative & Applied Ecology Group at UniMelb
Integrated Forest Ecosystem Research at UniMelb